# encoding: binary
#  Phusion Passenger - https://www.phusionpassenger.com/
#  Copyright (c) 2010-2017 Phusion Holding B.V.
#
#  "Passenger", "Phusion Passenger" and "Union Station" are registered
#  trademarks of Phusion Holding B.V.
#
#  Permission is hereby granted, free of charge, to any person obtaining a copy
#  of this software and associated documentation files (the "Software"), to deal
#  in the Software without restriction, including without limitation the rights
#  to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
#  copies of the Software, and to permit persons to whom the Software is
#  furnished to do so, subject to the following conditions:
#
#  The above copyright notice and this permission notice shall be included in
#  all copies or substantial portions of the Software.
#
#  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
#  IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
#  FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
#  AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
#  LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
#  OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
#  THE SOFTWARE.

begin
  require 'rubygems'
rescue LoadError
end
require 'socket'
require 'thread'
if (!defined?(RUBY_ENGINE) || RUBY_ENGINE == "ruby") && RUBY_VERSION < "1.8.7"
  begin
    require 'fastthread'
  rescue LoadError
    abort "You are using a very old Ruby version. You must install " +
      "the 'fastthread' gem to fix some bugs in the Ruby threading system: " +
      "gem install fastthread"
  end
end
require 'pathname'

class Exception
  def backtrace_string(current_location = nil)
    if current_location.nil?
      location = nil
    else
      location = "in #{current_location} "
    end
    current_thread = Thread.current
    if !(thread_id = current_thread[:id])
      current_thread.to_s =~ /:(0x[0-9a-f]+)/i
      thread_id = $1 || '?'
    end
    if thread_name = current_thread[:name]
      thread_name = "(#{thread_name})"
    end
    return "*** Exception #{self.class} #{location}" <<
      "(#{self}) (process #{$$}, thread #{thread_id}#{thread_name}):\n" <<
      "\tfrom " << backtrace.join("\n\tfrom ")
  end
end

class Dir
  # The current working directory may contain one or more symlinks
  # in its path. Both Dir.pwd and the C getcwd() call resolve symlinks
  # in the path.
  #
  # It turns out that there is no such thing as a path without
  # unresolved symlinks. The shell presents a working directory with
  # unresolved symlinks (which it calls the "logical working directory"),
  # but that is an illusion provided by the shell. The shell reports
  # the logical working directory though the PWD environment variable.
  #
  # This method tries to use the PWD environment variable if it
  # matches the actual working directory.
  #
  # See also:
  # https://github.com/phusion/passenger/issues/1596#issuecomment-138154045
  # http://git.savannah.gnu.org/cgit/coreutils.git/tree/src/pwd.c
  # http://www.opensource.apple.com/source/shell_cmds/shell_cmds-170/pwd/pwd.c
  def self.logical_pwd
    physical_pwd = Dir.pwd
    logical_pwd = ENV['PWD']
    if logical_pwd.nil? || logical_pwd.empty?
      return physical_pwd
    end

    # Check whether $PWD matches the actual working directory.
    # This algorithm similar to the one used by GNU coreutils.
    begin
      logical_stat = File.stat(logical_pwd)
      physical_stat = File.stat(physical_pwd)
      if logical_stat.ino == physical_stat.ino &&
         logical_stat.dev == physical_stat.dev
        logical_pwd
      else
        physical_pwd
      end
    rescue SystemCallError
      physical_pwd
    end
  end
end

class File
  # Dir.pwd resolves symlinks. So in turn, File.expand_path/File.absolute_path
  # do that too. This method fixes that by using Dir.logical_pwd.
  if File.respond_to?(:absolute_path)
    def self.absolute_logical_path(path, base = Dir.logical_pwd)
      return File.absolute_path(path, base)
    end
  else
    def self.absolute_logical_path(path, base = Dir.logical_pwd)
      return File.expand_path(path, base)
    end
  end
end

module Signal
  # Like Signal.list, but only returns signals that we can actually trap.
  def self.list_trappable
    ruby_engine = defined?(RUBY_ENGINE) ? RUBY_ENGINE : "ruby"
    case ruby_engine
    when /jruby/
      result = Signal.list.dup
      result.delete("QUIT")
      result.delete("ILL")
      result.delete("FPE")
      result.delete("SEGV")
      result.delete("USR1")
      result.delete("IOT")
    else
      result = Signal.list.dup
      result.delete("ALRM")
      result.delete("VTALRM")
    end

    # Don't touch SIGCHLD no matter what! On OS X waitpid() will
    # malfunction if SIGCHLD doesn't have a correct handler.
    result.delete("CLD")
    result.delete("CHLD")

    # Other stuff that we don't want to trap no matter which
    # Ruby engine.
    result.delete("STOP")
    result.delete("KILL")
    result.delete("EXIT")

    # Profilers such as ddtrace and stackprof use this signal, so removing the
    # the handler causes the Ruby process to crash when profilers are operating.
    # See https://github.com/phusion/passenger/issues/2489 for details.
    result.delete("PROF")

    return result
  end
end

module GC
  if !respond_to?(:copy_on_write_friendly?)
    # Checks whether the current Ruby interpreter's garbage
    # collector is copy-on-write friendly.
    def self.copy_on_write_friendly?
      return false
    end
  end
end
